<p>JeSuis, MATLAB is a good choice for geology. You might also pick up Python - a lot of the coding style is very similar, and it’s open-source, so if you go to a company that won’t pay for your MATLAB license (which SUCKS, btw), you don’t end up having to start over from scratch. Those are probably the biggest two in the earth sciences, setting aside things like Fortran, which just, well, hurt.</p>